Not really. I think that's a reach at best. Mercedes didn't break into anyone's house to steal any art. It was right there on the street for all to see. The fact that you're even defending this action on a board that started to celebrate illegal graffiti is funny to me. They cant have it both ways. Either go legit, copyright your name and trademark or stick to graff, remain anonymous and just be happy you got the free exposure.
E: Not for nothing but the irony isn't lost on me, the fact that you support socialist ideals where everything belongs to everyone yet pick this hill to die on is pretty humorous.